Can a subwoofer cause problems with my other equipment by being near them? Is this ok that I have my M22 on top of my subwoofer? I have a box in between them so its like:
|BS|
|BS|
|BOX|
|Sub|
|Sub|

Also I will have the cables from my surrounds go right by the subwoofer, brushing against it, is that ok?

The M22 is magnetically shielded, so its magnets will not affect the sub, and vice versa. The only problem I see putting speaker on a subwoofer is that the sub can cause unwanted vibrations in the M22's cabinet, which can in turn affect the sound.

Also, there's no problem running your speaker (or any) cables right next to the subwoofer. When it comes to magnetic fields and wires, you only really need to worry if the magnet is moving in relation to the wire.

The only real problem that I can anticipate is some distortion in your tube TV if it is too close to the set. Subs are usually not shielded, and can cause the electrons in the tube to bend towards or away from the large magnet in the sub's driver. Other than that, assuming your cables are well shielded, you shouldn't have any problems that I know of. Hopefully others will chime in if I have missed something.

When I upgraded to the EP500 I began experiencing some interference with FM reception. I had to run a 75ohm cable away from the sub and connect it to the FM antenna. Other than that, everthing else was fine.